Some manufacturers chose to change the socket in order to make the sleeve contact as the ground line (OMTP), while others chose to leave the ground contact where it was and squeeze the new channel in on the sleeve (CITA). Overview: The 3.5 mm stereo y-splitter cable allows you to easily connect your stereo headset & Mic to a PC audio port and mic port at the same time. There are different types of 3.5mm audio jack available with different application like TS, TRS, and TRRS, but the most common that we see in daily life is TRS and TRRS. Also, for hobbyists 3.5mm audio jack is a useful components for projects that plug into headphone jacks. CTIA is by default required for Android device manufacturers. Please be kindly noted that it's only compatible with CTIA standard Android headphones, do NOT compatible with CTIA standard Apple Earbuds. If the user manual is not available, or does not contain the info, try a Google search for phone model. 3.5mm 4pole to 3.5mm 4pole (CTIA TO OMTP 3.5mm adapter) This means Apple headphones to all Android (Nokia standard) smartphone or tablets. On iOS, you can listen to something, unplug the headphones, do something, plug them back in, hit the play button and you carry on where you left off. Also Android seems to be bad at remembering the last audio app that was open. AHJ/CTIA is used by: Apple, HTC, LG, Blackberry, latest Nokia, latest Samsung, Jolla, Sony (Dualshock 4), Microsoft (including Surface and XboxOne controller with chat adapter) most Android phones. CTIA jacks have improved compatibility to support not only AHJ but also OMTP. Android not so much - you have to manually open the app for it to work. Wikipedia has a short overview for which device uses which standard. Because this is the most compatible, most Headset Buddy products are CTIA unless otherwise stated. HEADSET TO PC ADAPTER - Use Your Favorite 3.5mm Smartphone Headset with your PC Computer. However the best method to verify which headset jack standard your phone uses is the check the phone’s user manual. or The other way round Android headphones to Apple items. If you have an iPhone or Android most likely your phone is AHJ. In The Box: 3.5mm female to 2 male Headphone Mic Audio Y Splitter Cable. CTIA, named after The Wireless Association, which replaced AHJ and has the same pinout. One called CTIA, and another known as OMTP. Source: All About Windows Phone. -Only compatible with CTIA standard Android headphones, do NOT compatible with CTIA standard Apple Earbuds.-Not compatible with Beats headphone and Apple headphone.